Aqueous lubricants for metal working



Unitcd States Patent 3,501,404 AQUEOUS LUBRICANTS FOR METAL WORKINGMorton H. Klaiber, Tonawanda, and Anton S. Pater, Williamsville, N.Y.,assignors to Union Carbide Corporation, a corporation of New York NoDrawing. Continuation of applications Ser. No. 514,121, Dec. 12, 1965,and Ser. No. 742,981, June 27, 1968. This application May 5, 1969, Ser.No. 830,181

Int. Cl. Cm 1/06 US. Cl. 252-495 9 Claims ABSTRACT OF THE DISCLOSURE Alubricant for metal working which is an aqueous emulsion containing anemulsifier and an olefin polymer having a molecular weight in the rangeof about 1,500 to 25,000, the olefin polymer being the major organicconstituent of the emulsion and being present in an amount of about 0.1to about 25 weight percent of the emulsion.

This application is a continuation of Ser. No. 514,121, filed Dec. 12,1965, and Ser. No. 742,981, filed June 27,

1968, and now abandoned.

This invention relates to aqueous base lubricants in metal workingapplications.

A metal working lubricant performs two principal functions: (1) reducesthe friction between moving metal surfaces in contact with each other,such as the chip and the toolface, for example, and (2) removes the heatgenerated during the time the metal is worked. In addition, a lubricantalso prevents chip build-up on the cutting tool, washes away metal chipsas they are formed, and also provides some degree of rust protection.

Metal working lubricants generally fall into two categories: (A) theso-called heavy-duty lubricants or fluids which comprise mineral oil andorganic sulfur, chlorine, or phosphorus compounds added thereto, and (B)aqueous base lubricants. The former are employed with ferrous metalwhere high unit pressures and high localized temperatures areencountered in instances such as broaching, tapping, threading, etc.These heavy-duty lubricants are not employed for high speed operationswhere excessive heat is generated, because of their relatively poor heattransfer properties. In addition, the mineral oil base lubricants arenot recommended for use on non-ferrous metals because of the possibilityof corrosive attack and/or staining. The aqueous base lubricants, on theother hand, are well suited for high speed operations such as drillingand turning where during the machining operations the load is relativelylight; however, heretofore aqueous base lubricants capable ofsatisfactory performance in heavy-duty applications have not beenavailable.

It is an object of this invention to provide an aqueous base lubricantwhich is capable of heavy-duty performance such as broaching, tapping,threading, and the like, not only for ferrous metals such as steel andthe various steel allows, but also for non-ferrous metals such ascopper, aluminum, brass, bronze, and the like.

It is another object to provide an aqueous base lubricant whichpossesses exceptional anti-wear and anti-weld properties.

It is a further object to provide a method for metal working employingaqueous base lubricants which attains machining results at leastequivalent to those obtainable with mineral oil base lubricants andwhich at the same time provides improved heat transfer away from themachining area.

Still other objects of the present invention will become readilyapparent to the skilled artisan upon reference to the ensuingspecification and the claims.

3,501,404 Patented Mar. 17, 1970 The foregoing objects are achieved byemploying as a metal working lubricant an aqueous emulsion comprising asthe major organic component from about 0.1 to about 25 weight percent ofa polyolefin having a molecular Weight in the range from about 1,500 toabout 25,000 and also an emulsifying agent. Preferably the polyolefin isselected from the group consisting of polyethylene and polypropylene. Itis also preferred that the amount of the polyolefin in the emulsionranges from about 0.2 to about 3 Weight percent. For heavy dutyoperation, however, the most preferred range is from about 1 to about 3weight percent.

Any polyolefin can be employed to form the foregoing aqueous emulsions.In the various embodiments of this invention the performance of thepolyolefin is independent of the breadth of the molecular weightdistribution, the polymer density, or the polymer structure.

A suitable polyolefin for the purposes of the present invention is onehaving molecular weight in the range from about 1,500 to about 25,000and a melting point which preferably does not exceed about 200 C.Typical of such polyolefins are the homopolymers and copolymers of analpha olefin containing from 2 to about 12 carbon atoms such asethylene, propylene, butylene, and the like. Because of their favorableemulsification properties, polyolefins containing on the average atleast one polar group for every four polyolefin molecules are preferred.

The polyolefins may be obtained within the aforementioned molecularweight range by direct polymerization, emulsion polymerization, or bythe pyrolysis of a higher molecular weight polyolefin.

The latter technique is preferred since the pyrolysis of the relativelyhigher molecular weight polymers creates terminal vinyl unsaturationwhich is readily available for reaction with an ethyletnicallyunsaturated polar monomer such as maleic anhydride or thioglycolic acid,as taught by US. Patents 2,766, 214 and 3,144,348, thereby rendering theresulting polyolefin readily emulsifiable.

Another valuable technique for the preparation of emulsifiable polymershaving a suflicient number of polar groups is by oxidation, with orwithout a catalyst, so as to create pendant carboxylic groups on thepolymer chain along with ketone, aldehyde, and hydroxyl groups.

Other suitable emulsifiable polyolefins are the block copolymers formedby reacting ethylene oxide with polyethylene so as to produce hydroxylterminated polymers in accordance with the teachings of U .S. Patent2,921,920. Also suitable polyolefins are the ethylene-alcohol telomersreacted with maleic acid as taught by US. Patent 2,766,214.

Similarly, the requisite amount of polar groups can be introduced intothe aforementioned homopolymers and copolymers of alpha olefins by thecopolymerization of the resulting polyolefins with unsaturated monomerscontaining the ethylene linkage such as ethylene acrylate, styrene,bicycloheptene, vinyl acetate, acrylic acid, methacrylic acid, and thelike.

In addition, the direct polymerization to and/or bydrolysis of theolefin polymers mentioned above can impart the necessary amount ofpolarity to the polymer chain so as to make the polymers emulsifiableand the resulting emulsion stable.

Emulsion polymerization can be carried out by emulsifying the olefinstarting material in water by means of a suitable emulsifier andthereafter polymerizing the olefin at elevated pressures and temperaturein the presence of a polymerization catalyst. Illustrative emulsionpolymerization processes are set forth in US. Patents 2,342,400;2,542,783; 2,592,526; and 2,703,794.

Thus it can be readily seen that many ways are known and are availablefor making polyolefins which are suitable for use in the presentinvention. The foregoing listing is illustrative only and is notintended to be in any way exclusive or limiting.

The aqueous polyolefin emulsions can be anionic, nonionic, or cationic.Thus any compatible emulsifying agent can be employed, however,non-ionic emulsifiers are preferred for metal working purposes.

The non-ionic emulsifiers contemplated herein are organic compounds of arelatively high molecular weight and consisting of a hydrophobic portionto which is attached a solubilizing or hydrophilic portion containinggroups such as ether links (COC), hydroxyl groups (-OH), carbonyloxygroups and the like.

Specifically contemplated within the above definition are surfactantshaving as the hydrophilic moiety one or more chains containing one ormore alkyleneoxy groups. These surfactants have the general formulawherein R is the hydrophobic portion of an aliphatic alcohol containingfrom about 8 to 22 carbon atoms or an alkylatecl phenol containing fromabout 4 to about 22 carbon atoms in the alkyl group thereof, Y is analkyleneoxy chain, H is a hydrogen atom bonded to an oxygen atom of thealkyleneoxy chain, and y is an integer from 1 to about 6, and preferablyfrom 1 to 4.

Typical aliphatic alcohols are octyl alcohol, nonyl alcohol, decylalcohol, coco alcohol (a mixture of C to C alcohols), dodecyl alcohol,oleyl alcohol, tallow alcohol (a mixture of C to C alcohols), octadecylalcohol, 2,6,8-trimethyl-4-nonyl alcohol, and the like.

Typical alkylated phenols are butylphenol, pentylphenol, hexylphenol,otcylphenol, nonylphenol, dodecylphenol, hexadecylphenol,octadecylphenol, nonadecylphenol, and the like.

By the term alkyleneoxy chain as used herein is meant a chain containingone or more alkyleneoxy groups which are divalent alkylene groups suchas methylene, ethylene, propylene, butylene, and the like, bonded to anoxygen atom in a manner such that one of the valences of the alkyleneoxygroup is from an oxygen atom and the other is from a carbon atom.Typical alkyleneoxy groups are methyleneoxy (-CH O-), ethyleneoxy (C HO), propyleneoxy (C H O), butyleneoxy (C H O-) and the like.

Preferred non-ionic emulsifiers for the instant formulations are thepolyalkylene glycol ethers containing from about 4 to about 80 moles ofalkylene oxide. Illustrative preferred non-ionic surfactants are thenonylphenyl polyethylene glycol ethers containing about 4 moles ofethylene oxide, the trimethylnonyl polyethylene glycol ethers containingabout 6 moles ethylene oxide, the nonylphenyl polyethylene glycol etherscontainng about 7 moles of ethylene oxide, mixed polyalkylene glycolethers containing about 60 moles of a mixture of ethylene oxide and1,2-propylene oxide in a mole ratio of about 2:1, and the like.

Typical cationic emulsifiers suitable for the present emulsificationmethod are the combination of an organic acid, such as acetic acid orthe like, with an amine such as cyclic imidazoline, tertiary ethoxylatedsoya amine, tallow polyethoxylated amine having two ethoxy units in thepolyethoxylated portion of the molecule, the oleyl polyethoxylatedamines having two to five ethoxy units in the polyethoxy portion of themolecule, soya polyethoxylated amine having five ethoxy units in thepolyethoxy portion of the molecule, and the like.

The anionic emulsifiers contemplated herein are amine soaps, and thelike. These soaps are formed by the reaction of an amine with a fattyacid such as oleic acid,

palmitic acid, lauric acid, myristic acid, the tall oil acids, the palmoilacids, or the like, in about stoichiometric amounts and at roomtemperautre or at a slightly elevated temperature. Suitable amine soapsare triethanolamine stearate, triethanolamine oleate, triethanolaminecoconut oil soap, isopropanolamine oleate, N,N-dimethyl ethanolamineoleate, 3-methoxypropyl amine oleate, morpholine oleate and the like.

A wide variety of aqueous polyolefin emulsions has been investigated andtheir suitability for the practice of the present invention has beenascertained. These emulsions are characterized below and will bereferred to subsequently by code letter in the interests of conciseness.In addition, the conventional cutting oils employedfor purposes ofcomparison are similarly char acterized.

CHARACTERIZATION OF CUTTING FLUIDS Emulsion A-An aqueous, non-ionicemulsion of chemically inert, low molecular weight polyethyleneemulsified by a polyoxyethylene derivative of an aliphatic compound.

Emulsion B-An aqueous, anionic emulsion of medium molecular weightpolyethylene emulsified by a fugitive emulsifier.

Emulsion C-An aqueous, non-ionic emulsion of highmelt, high-densitypolyethylene (molecular weight: 6,5008,400) which has been cracked andair-oxidized.

Emulsion DAn aqueous, anionic emulsion of cracked, high-densitypolyethylene (molecular weight: about 2000) modified with about 5 weightpercent maleic anhydride and emulsified with an amine-fatty acidemulsifier.

Emulsion E-An aqueous, cationic emulsion of cracked, high-densitypolyethylene (molecular weight: about 2000) modified with about 5 weightpercent maleic anhydride and emulsified with an ethoxylated primaryfatty acid amine and acetic acid.

Emulsion PAn aqueous, non-ionic emulsion of cracked, high-densitypolyethylene (molecular weight: about 2000) modified with about 5 weightpercent maleic anhydride and emulsified with a mixture of nonylphenylpolyethylene glycol ethers containing about 4 and about 7 moles ofethylene oxide and with morpholine.

Emulsion G-An aqueous, non-ionic emulsion of cracked, high-densitypolyethylene (molecular weight: about 2000) modified with about 5 weightpercent maleic anhydride and emulsified with a mixture of nonylphenylpolyethylene glycol ethers containing about 4 and about 7 moles ofethylene oxide and with Z-methoxypropyl amine.

Emulsion I-IAn aqueous, anionic emulsion of lowdensity polyethylene(molecular weight: about 16,000) prepared by emulsion polymerization.

Emulsion I-An aqueous, non-ionic emulsion of lowdensity, polyethylene(molecular weight: about 24,000) prepared by emulsion polymerization.

Emulsion JAn aqueous, non-ionic emulsion of low density polyethylene.

Emulsion K-An aqueous, cationic emulsion of low density polyethylene.

Emulsion L-An aqueous, non-toxic emulsion of polyethylene having arelatively low content of emulsifiers.

Emulsion MAn aqueous, non-ionic emulsion of polyethylene.

Emulsion N--An aqueous, non-ionic emulsion of polypropylene.

Emulsion PAn aqueous styrene-butadiene copolymer latex.

Emulsion QAn aqueous carboxylated styrene-butadiene latex.

Emulsion RAn aqueous polyisoprene latex (natural).

Emulsion S-An aqueous polyvinylidene chloride latex.

Oil AA petroleum oil conventionally used neat for tapping and threading.Contains as active extreme pressure agents about 3 weight percent sulfurand about 1 weight percent chlorine.

Oil BA soluble cutting oil containing a very high percentage of extremepressure and anti-weld fats and additives.

Oil C-Paraffin oil having a viscosity index of about 90. Contains noadditives.

Oil DWater insoluble polyalkylene glycol.

The evaluation of the lubricant formulations and the method of thisinvention were carried out using a Falex Tester. This test equipmentcomprises a replaceable A- inch diameter shaft (No. 8 soft steel pin)which is revolved at 290 r.p.m. between two steel V-blocks. The shaftcan be machined from SAE 3135 steel having a Rockwell B hardness of 87to a 8-10 RMS finish, and the two V-blocks can be machined from AISIC-1137 steel having a Rockwell C hardness of 20 to a 6-8 RMS finish(Method 1). In the alternative, the shaft can be machined from M-2 toolsteel having a Rockwell C hardness of 60 to a 12-14 RMS finish, and thetwo V-blocks can be machined from 440C stainless steel having a RockwellC hardness of 60 to a 12-14 RMS finish (Method II).

The V-blocks are postioned so that they can be forced against the shaftby a notched loading wheel. The adjustment of the loading wheel duringthe test in order to maintain a predetermined load is indicative of thewear on the test shaft. The adjustment of each notch or tooth on theloading wheel indicates 0.000057 inch of wear of the test shaft.

During a test both the shaft and the V-blocks are immersed in thelubricant to be tested.

The operational steps during the test are as follows:

(1) The test is commenced by revolving the shaft between the V-blocksfor 3 minutes at 100 1b. load.

The present invention is further illustrated by the following examples.

. Example 1 Using the Falex Tester and employing Method I describedabove various polymeric emulsions were evaluated for load carrying andanti-weld properties. The emulsions were aqueous and contained about 0.5weight percent solids. The experimental results are set forth in Table Ibelow.

TABLE I Seizure load, Emulsifier Emulsion Type of emulsion pounds type2,500 a R. Natural Latex 2,500 a Q, Carboxylated SB R.... 2,750 a S.Polyvinylidene Chloride... 1,750 a F. Modified Polyethylene 4,500 n+8 A.Polyethylene- 4, 500 n D. Modified Polyethylene. 4, 500 a+a OPolyethylene ,500 n B... ..d 4,000 a. 1-..- .do. 4,000 n H- .d 3, 750 aI. d 4, 250 n K. .d 4, 500 c M- .do. 4,500 n L. do 4,250 n NPolypropylene 4, 250 n 1 n=Nonionic; a=Anionic; c=Cationic.

From the data in Table I it is readily apparent that polyolefinemulsions possess excellent load carrying and antiweld properties.

Example 2 The anti-wear properties of aqueous polyolefin ern-ulsionswere evaluated using the Falex Tester and employing Method I describedabove. The experimental results are compiled in Table II below.

TABLE II Cumulative teeth adjusted to compensate for wear at loadincrements oi Wt. percent eizur 1. Emulsifier load in 3, 000 3, 500 4,000 4, 500 type pounds lbs. lbs. lbs. lbs.

n 4, 250 95 185 1, 000 0 4, 500 115 220 n 4, 000 160 540 a 3, 750 20 110n 4, 500 15 125 435 n 4, 250 70 190 520 n 4, 500 70 170 400 a 4, 000 0 0Seized I1 4, 500 0 0 20 170 a 4, 500 0 0 15 155 n+a 4, 500 0 30 125 270n 250 15 180 760 a 1, 750 110 n 4, 500 0 0 10 165 a 500 20 n+a 4, 000 20110 1 n=Nonionic; a=Anionic; e=Oationic.

(2) The load is the increased each minute in 100 lb. increments up to1000 lbs.

(3) After 1000 lbs. load is reached, further loading is done in 250 lb.increments each minute until seizure or a maximum load of 4500 lbs. isattained.

(4) Torque and temperature are recorded each minute, and

(5) During each one minute interval the wear on the test shaft is notedand recorded as the number of notches on the loading wheel that have tobe adjusted in order to maintain the desired load.

After the test the average scar width on the V-blocks is measuredmicroscopically and the contact pressure in pounds per square inchcalculated from the following:

Gauge load seizure bearing load, lbs. car length, in. sear width, in.

=bearing load, lbs.

=pounds per sq. inch scar length 0.5 inch The performance of apolyethylene emulsion at various solids concentrations was evaluated inthe Falex Tester employing Method I. The experimental data are compiledin Table III below.

TABLE III Cumulative teeth adjusted to compensate for wear at loadincrements Seizure Emulsion A Diluted with load in 3,000 3,500 4, 0004,500 Water to: pounds lbs. lbs. lbs. lbs

3.0 wt. percent solids. 4, 500 0 30 380 1.0 wt. percent solids. 4, 500 035 95 405 0.5 wt. percent solids- 4, 500 0 0 20 170 0.2 wt. percentsolids. 4, 500 0 0 10 0.1 wt. percent solids 2, 500 O The data indicatedthat at concentrations of from about 0.2 to 3.0 wt. percent solids theanti-weld prop erties exceed the limit of the test equipment. Optimumantiwear properties were obtained at 0.2 to 0.5 wt. percent solids, butthe anti-wear properties at higher concentrations are still very good.

Example 4 The contact pressures for various prior art lubricants and forthe lubricants of the present invention were determined in a FalexTester employing Method II described above. The experimental results areshown in Table IV, below.

TABLE IV Gage Avg. scar Contact load, lbs. width, Pressure Compositionof lubricant in water at seizure inches p.s.i.

' 3, 750 037 140, 000 Oil B diluted 15/1 with Water 4, 000 029 200,000Oil 3, 000 024 180, 000 Oil D 2, 500 016 220, 000 1.0 wt. percentsolids, Emul n 4, 000 021 270, 000 0.2 wt. percent solids, Emulsion F 2,500 015 240, 000 1.0 wt. percent solids, Emulsion A 4, 500 019 330, 0000.2 wt. percent solids, Emulsion A 3, 000 016 260, 000 0.2 wt. percentsolids, Emulsion D- 2, 750 016 240, 000

1.0 wt. percent triethanolamine (soap) 2, 750 026 150, 000

0.2 wt. percent triethanolamine (soa 2, 500 018 200, 000 1.0 wt. percentsolids, Emulsion N 3, 500 018 290, 000 0.2 wt. percent solids, EmulsionN 3, 250 018 270, 000

The foregoing data indicate that only with aqueous polyethylene andpolypropylene emulsions contact pressures above about 220,000 p.s.i.could be obtained. For this reason these emulsions are preferred.

Example The anti-wear and anti-weld properties of polyolefin lubricatingfluids were also evaluated in a tapping performance test. Theperformance of the lubricating fluids of this invention was comparedwith that of Oil A, a cutting .oil normally employed for tapping ofstainless steel.

Testing details:

Machine data4 radial drill; American'Hole Wizard.

Bar stock-304 stainless steel, 2 /2 x 1% x 12 inches.

Blind holes-Drilled with No. 7 (.201 in. dia.) drill, 1%

inches deep, 610 r.p.m. and 0.004 in/ revolution feed; dilutewater-soluble oil coolant.

Tap- 4 X 20 N.C.; H.S. grd. H3. 4 Flt. plug special for stainless steel,mfd. by Winter Bros, Rochester, Mich.

Tapping fixture-Adjustable torque clutch, Swedish Model SPV-SA-IE.

Lubricant evaluation:

(1) Tap full one inch deep blind hole to top of flute (an 80% thread,one inch deep).

(2) Tap speed 70 r.p.m.

(3) Lubricant is applied to completely fill the blind hole.

(4) After applied torque causes the tapping fixture to slip, the tap isreversed, and the hole cleared of chips and lubricant with an air hose(one tapping cycle completed).

(5) Lubricant is applied again and an additional attempt to tap is made(next tapping cycle).

(6) The number of cycles required to tap full one inch depth is taken asthe criteria of performance.

Conventional aqueous metal working fluids and other such as aqueoussuspensions of graphite or haloalkane resins could not be employed tosuccessfully tap under the above conditions. Similarly, suspensions ofnon-emulsifiable polyethylene, maleic anhydride modified polyethylene inkerosene, mineral seal oil, or mineral spirits were not satisfactory.The tapping results using Oil A and various aqueous polyolefin emulsionsare compiled in Table V below.

TABLE V Cycles nee.

to form full Hole Tapping lubricant evaluated in water 1 in. threadnumbers Oil A 3, 3, 3 57, 66, 112 Do 4, 4, 4 75,106,107 15 wt. percentsolids, Emulsion G 3 56 3 wt. percent solids, Emulsion G 2, 2, 2 51, 53,61 1 wt. percent solids, Emulsion G 4 52 3 wt. percent solids, EmulsionD 4 49 1 wt. percent solids, Emulsion D 5 50 25 wt. percent solids,Emulsion E 2 72 3 wt. percent solids, Emulsion E 2 75 1 wt. percentsolids, Emulsion E 3 74 20 wt. percent solids, Emulsion F- 2 62 3 wt.percent solids, Emulsion F- 3, 3 63, 71 1 wt. percent solids, EmulsionF. 3 64 1 wt. percent solids, Emulsion F plus 3 w percent triethyleneglycol 2 70 0.5 wt. percent solids, Emulsion F plus 3 wt.

percent triethylene glycol 5 108 The above data illustrate thesuitability of aqueous polyolefin emulsions as lubricants for tappingoperations.

Example VI TABLE VI Performance data Overall rating 1 Fluid and DilutionRatio Roughing cuts Finish cuts Excellent- Excellent. Fair r.

Good Excellent.

Oil A Fine tears Oil B (30/1 dilution) 1 wt. percent, Emulsion F Finetears--.

1 Fair, Good, Excellent.

The experimental results show that aqueous polyolefin emulsions are atleast equivalent in performance to heavy duty mineral oil baselubricants.

In addition to the active constituents discussed above in detail thelubricating compositions of this invention can also contain variousadditives which are conventionally employed to impart certain desiredproperties to the compositions. Among such additives are corrosioninhibitors, anti-foam agents, antibacterial agents, and the like.

The corrosion inhibitors that can be used are morpholine, the alkalimetal nitrites (e.g., potassium nitrite and sodium nitrite), the alkalimetal mercaptobenzothiazoles (e.g., the sodium salt ofmercaptobenzothiazole), the polyphosphates (e.g., hexametaphosphate),and the like.

Illustrative anti-bacterial agents are the chlorophenols, the neomycinsulfates, 6-acetoxy-2,4-dimethyl-m-dioxane, and the like. An aqueoussolution containing di(phenyl mercuric) ammonium propionate in an amountsuflicient to provide about 6 wt. percent of mercury.

Illustrative anti-foam agents are alcohols in the C to C range such as2-ethyl hexanol, surfactants having a low hydrophile/lipophile balance,and the like.

The manner in which the compositions of this invention are produced isin no way critical. That is, the components of the compositions can bemixed in any convenient sequence and in any suitable apparatus. Thetechniques applicable to producing conventional aqueous lubricantcompositions can be employed in producing the compositions of thisinvention.

The foregoing discussion and the examples are intended as illustrativeof the present invention. Other variations and modifications within thespirit and scope of this invention will readily present themselves tothe skilled artisan. For example, while the foregoing examplesillustrate the use of the instant method with ferrous metals, a verysevere test, the method of the instant invention is equally applicableto the working of metals such as copper, aluminum, bronze, brass, andthe like, where at least two metal surfaces are in movable contact witheach other.

We claim:

1. In the method for metal working which comprises providing at leasttwo metal surfaces in movea-ble contact with each other and applyingthereto a lubricating composition, the improvement consistingessentially of using as the lubricating composition an aqueous olefinpolymer emulsion containing an emulsifier and an olefin polymer having amolecular weight in the range of about 1,500 to about 25,000, the olefinpolymer being the major organic constituent of the emulsion and beingpresent in an amount in the range of about 0.1 to about 25 weightpercent of the emulsion.

2. The method in accordance with claim 1 wherein the olefin polymer isan ethylene polymer and is present in an amount in the range from about0.2 to about 3 Weight percent of the emulsion.

3. The method in accordance with claim 1 wherein the olefin polymer is apropylene polymer and is present in an amount in the range from about0.2 to about 3 weight percent of the emulsion.

4. The method in accordance with claim 1 wherein the emulsifier isnon-ionic and the olefin polymer is polyethylene, present in an amountin the range from about 0.2 to about 3 weight percent of the emulsion.

5. The method in accordance with claim 1 wherein the olefin polymer isan isoprene polymer.

6. The method in accordance with claim 1 wherein the olefin polymer is astyrene-butadiene copolymer.

References Cited UNITED STATES PATENTS 2,122,826 7/1938 Van Peski 252-552,142,980 1/1939 Hwijser et al. 25259 2,143,566 1/1939 Moser 252592,470,913 5/1949 Bjorksten et al 25249.5 2,965,596 12/1960 Sharf 260-2963,428,565 2/1969 Fischer 25259 3,078,237 2/ 1963 Creech et a1 25259 XDANIEL E. WYMAN, Primary Examiner C. F. DEES, Assistant Examiner US. Cl.X.R. 252--49.3, 55, 59

